Reader Submitted: Sum Waste: A Compostable Pen and Ink System Derived from Materials Found in Sewage

Every day, NYC turns 1.3 billion gallons of sewage into a material called biosolids by feeding it to microorganisms. Though once utilized to enrich soils, around 2.8 million pounds of biosolids has gone to landfill every day for the past ten years. Sum Waste proposes creating a sustainable industry out of it by producing bioplastics and a pigment from it instead.

The final form of this project is a sustainably designed pen and ink from materials derived from biosolids. The pen barrel is designed to be made of PHA, a soil compostable bioplastic that can be produced by feeding biosolids directly to bacteria. While this may seem like a future technology, the Dutch Water Authority is already producing it through their Energy and Raw Materials Factory. One of the designs from this initiative, MOURN by Studio Nienke Hoogvliet, is on display at the Cooper Hewitt.

More than just a material study, the Sum Waste pen is sustainable by design and function. The PHA pen barrel interacts with its corresponding refill to retract like a normal pen, but with a twist that saves a lot of carbon.

Existing retractable pens require multiple parts made from different materials to function, making the interior workings of these pens intimidating to consumers. The Sum Waste pen is made of just two components; the PHA barrel and a standard ink refill with a heat-molded top. The helical channel in the pen barrel bends the ink refill to create just enough friction that the pen tip will not retract when writing. With a slightly harder push of the pen against a surface, however, the tip smoothly retracts. To expose the tip again, simply push on the flat top of the refill. The flat top of the refill is heat-molded from the existing polypropylene tube that holds the ink so as not to add any extra parts to its production. This design, combined with the helical channel in the barrel, eliminates all of the small parts found in existing retractable pens. This makes the pen less carbon heavy to produce, easier to recycle, and saves lot of headache for consumers that find retractable pens confusing and intimidating to refill or dispose of properly.

Users purchase the components separately, putting the barrel and refill together themselves. This is meant to highlight the different material streams, life cycle lengths, and functions that each component serves. Users can employ the same barrel for multiple ink colors, or keep their ink if they want a new barrel. To dispose the pen, users simply compost the barrel and/or recycle the refill to be reclaimed in full. The pen is over an inch shorter than its competitors yet is easy to hold and contains the same amount of ink as normal ball point pens.

Right Waste Poster

Credit: Garrett Benisch

Assembling the Pen

The pen refill slides in the helical channel of the barrel with a simple push.

Credit: Garrett Benisch

Biological Nutrient

The PHA pen barrel can be composted with food and yard scraps or even buried in a backyard where it will decompose in a matter of weeks.

Credit: Garrett Benisch

Technical Nutrient

The ink refill is a standard brass and polypropylene component with a simple alteration on top of it. This component can be fully recycled.

Credit: Garrett Benisch

Solar Carbonizer1

Small samples of biosolids were carbonized by focusing the sun’s rays through a fresnel lens taken from an overhead projector.

Credit: Elizabeth Bridges

Sum Waste Components

Credit: Garrett Benisch

Making Ink

The carbonized biosolids pigment was hand ground and suspended in a natural oil to create a rudimentary ink. This ink is featured on every Sum Waste business card.